How to Prepare for the Test

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Why the Test is Performed

There are 2 types of the Coombs test:

Direct

Indirect

The direct Coombs test is used to detect antibodies that are stuck to the surface of red blood cells. Many diseases and drugs can cause this to happen. These antibodies sometimes destroy red blood cells and cause anemia. Your health care provider may recommend this test if you have signs or symptoms of anemia or jaundice (yellowing of the skin or eyes).

Anemia

Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Different type...

The indirect Coombs test looks for antibodies that are floating in the blood. These antibodies could act against certain red blood cells. This test is most often done to determine if you may have a reaction to a blood transfusion.

Normal Results

A normal result is called a negative result. It means there was no clumping of cells and you have no antibodies to red blood cells.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

An abnormal (positive) direct Coombs test means you have antibodies that act against your red blood cells. This may be due to: